There are many strange components to the lawsuit threatening to stop the release of “The Hangover 2″ this weekend.

First, it’s over a face tattoo. Mike Tyson, who appeared in the first “Hangover,” doesn’t appear in in the sequel—but his face tattoo shows up on Ed Helms as pictured below.

Second, the lawsuit isn’t from Tyson, but from the tattoo artist who inked it on Tyson’s face. Artist S. Victor Whitmill claims to hold a copyright on the ink on Tyson’s face, and has sued Warner Brothers with a requested injunction to stop the film’s release.

Third—and certainly strangest—he actually seems to have a credible claim on Tyson’s face.

The Hollywood Reporter uncovered a copy of Whitmill’s complaint. Not only does he have a credible trademark registration on Tyson’s face tattoo, but he has a signed released from Tyson granting Whitmill the rights to the design on his face. From THR: “Whitmill attaches to the lawsuit his copyright registration for the ‘Original Tattoo,’ as well as Tyson’s signed release granting rights in the work.”

Sure, the design ornamenting Tyson’s visage is distinct, but this is Iron Mike we’re talking about, here. Why would he volunteer the rights to his own facial appearance to someone else? As we’ve all seen in the “Tyson” documentary, the man has a (seriously creepy) soft side. Maybe he was feeling generous.

At any rate, Pop Eater today gets a legal opinion from a Hollywood attorney, who assures us that “The Hangover 2″ will come out on schedule. “Using the tattoo in the movie is simply part of the joke. It is also transformative in that it makes use of the tattoo in a scene where it adds value to the meaning of the original design,” the attorney says, concluding “no court will order an injunction.”

So let that be a warning: Next time, before you try to convince a heavyweight champion to assign you the rights to part of his face, remember it might not actually hold up in court.